1. Field of the Invention
The device of the present invention relates to a simple and improved control for automatically terminating a heating operation such as terminating the heating operation in an electric egg cooker when the eggs are cooked to the desired degree.
2. Description of the Prior Art
A very popular automatic egg cooker of the type with which the present improved control is to be used has been extensively sold for more than fifteen years. Such an egg cooker is disclosed in U.S. Pat. Nos. 2,761,375--Jepson and 3,143,639--Wickenberg et al. In such prior art egg cooker (or baby bottle warmer) a control which is manually actuated to start the heating operation is actuated, upon a rise in temperature that would indicate the heating operation was completed, to terminate such operation. To this end, the degree to which eggs were cooked was determined by placing selectively different amounts of water into an egg cooking vessel and relying upon the time it took to evaporate this water to determine the duration of the heating cycle. The design was such that as long as there was water in the vessel being heated, the temperature of the bottom of the vessel would not substantially exceed the boiling temperature of water, but as soon as all the water was evaporated the temperature would rise rapidly and this rapid change in temperature of the bottom of the vessel was utilized to terminate the heating or cooking operation.
In such prior art egg cookers, it was necessary to provide a complicated switching means and temperature response control means which could be manually actuated to the closed position to supply energy to an electric heating element, then would remain in such position until the heating operation was completed, and thereafter the switching means would interrupt the electric circuit to the heating element with a snap action. The controls of such prior art arrangements worked very well but they were much too expensive and complicated.
It would be desirable to provide a temperature responsive control means for automatically controlling a heating device which device is less expensive to manufacture, and yet which is equally as fool-proof in operation as the arrangement disclosed and claimed in Jepson U.S. Pat. No. 2,761,375 and Wickenberg et al. U.S. Pat. No. 3,143,639. To accomplish this the improved control means should use conventional switches which are made by the millions and are relatively inexpensive and which could be employed to perform all the functions of the more expensive and elaborate prior art controls.